A method for improving vehicle battery state-of-charge (SOC) for initial vehicle customer delivery is disclosed. The method is focused on vehicle assembly plant practices and ensuring that battery discharge is minimized or eliminated during the vehicle assembly process. The method includes determining the available maximum percentage of duty cycle voltage output from the vehicle alternator and determining a minimum idle boost speed necessary to provide minimum discharge or positive charge to the battery when the vehicle's accessories are in the "on" state during vehicle assembly. The method further includes programming the vehicle's controllers to force the maximum percentage of duty cycle voltage output available and the minimum idle speed necessary to provide minimum battery discharge or positive charge during the earliest part of the vehicle life.